SANTA ROSA, Calif. As wildfires ravage communities in Northern California, thousands who have evacuated are wondering when they can go home and others have no home to go back to.

Starting late Sunday, at least 22 wildfires swept through several counties, including Napa and Sonoma, killing at least 23 people and injuring more than 100. As of late Wednesday, the Sonoma Sheriffs Office told HuffPost that hundreds of people are still unaccounted for. They said that power outages and intermittent cell phone service may be preventing people from contacting friends and relatives.

California Gov. Jerry Brown declared a state of emergency Monday, and thousands of people have since been forced to flee their homes in mandatory evacuations . By Wednesday morning, at least 3,500 homes and businesses had been destroyed and nearly 170,000 acres burned, according to Daniel Berlant of the California Department of Forestry and Fire Protection.

For those who are evacuating, some will have friends or family to stay with, others can afford a hotel for a few nights but for the most vulnerable groups, such as the elderly and the poor, many are staying in one of the dozens of Red Cross shelters that have been set up in the region.

At one such shelter at the Sonoma County Fairgrounds in Santa Rosa one of the hardest-hit cities, where smoke still hung thick in the air Tuesday afternoon about 300 people had spent the night, according to Jim Bray, Red Cross volunteer and assistant manager at the shelter. Many of those staying at the fairgrounds were older residents from retirement communities.

We havent heard anything we think thats a good sign, said Candace Hayes, who evacuated from Vigil Light, an affordable housing community for the elderly and disabled, on Monday. Hayes, who is blind, said her biggest concern was going home. Id like to go home.

Thats the one thing I dont like: We dont know whats going on or whats going to happen, she added, as she petted her service dog on the head. Its all kind of up in the air.

HuffPost spoke to several evacuees at the shelter, and a common concern was simply that people wanted to see their homes again, to make sure they were still standing.

Theres a large evacuation area in Santa Rosa, and even if your house isnt destroyed, the police are not letting people back in there. That causes a lot of consternation for people, because they dont know, Bray told HuffPost, noting that over 500 homes have been lost in the city, about 50 miles north of San Francisco. Other people know their houses have been burned, but theyre still being kept out.